PDFStream Class

class PDFStream : PDFObject

Namespace:com::datalogics::PDFL

Inherits from:: PDFObject

Detailed Description

Represents a stream of data within a PDF document. All objects in a PDF document are built from a collection of simpler objects that represent fundamental datatypes like numbers, strings and arrays.

PDFObject and its subclasses allow direct access and manipulation of these simple objects. Some subclasses represent single data elements (e.g. PDFInteger represents a single integer value); other subclasses represent a collection of PDFObjects (e.g. PDFArray is an indexed array of data elements).

A PDFStream represents a stream of unsigned bytes, and may be inserted into any collection object. It includes a dictionary that describes how the data in the stream is encoded and other useful information about the stream. A PDFStream is always an indirect object.

PDFStreams can be encoded using built-in filters. These filters include compression schemes for most popular image formats, and text encoding translators to permit safe transmission of the document over the Internet. The data in a PDFStream will be automatically encoded when it is created; the user can read either the encoded (raw) or decoded (filtered) data.

PDFStreams can be used for any large collection of data that need not be read into memory all at once, including image data, multimedia data or XML markup.

Referenced by

Form ICCBasedColorSpace Image PostScript PostScriptCalculatorFunction

Uses types

BaseInputNozzle Document OutputNozzle PDFArray PDFDict PDFObject PDFObjectEnumProc

Constructor & Destructor Documentation

PDFStream(BaseInputNozzle nozzle, Document doc, PDFDict encoding_dict, PDFArray encoding_params)

Parameters

nozzle: BaseInputNozzle: An input nozzle providing the stream data.
doc: Document: The Document in which this PDFStream is created.
encoding_dict: PDFDict: A PDFDict describing the encoding filters for this stream, or null for no encoding.
encoding_params: PDFArray: A PDFArray describing parameters for the encoding filters, or null for defaults.

Creates a new PDFStream in the specified document.

PDFStream(BaseInputNozzle nozzle, PDFObject docFromObj, PDFDict encoding_dict, PDFArray encoding_params)

Parameters

nozzle: BaseInputNozzle: An input nozzle providing the stream data.
docFromObj: PDFObject: A PDFObject whose document will contain the new PDFStream.
encoding_dict: PDFDict: A PDFDict describing the encoding filters for this stream, or null for no encoding.
encoding_params: PDFArray: A PDFArray describing parameters for the encoding filters, or null for defaults.

Creates a new PDFStream in the same document as the given PDFObject.

PDFStream(java.io.InputStream stream, Document doc, PDFDict encoding_dict, PDFArray encoding_params)

Parameters

stream: java.io.InputStream
doc: Document
encoding_dict: PDFDict
encoding_params: PDFArray

PDFStream(java.io.InputStream stream, PDFObject docFromObj, PDFDict encoding_dict, PDFArray encoding_params)

Parameters

stream: java.io.InputStream
docFromObj: PDFObject
encoding_dict: PDFDict
encoding_params: PDFArray

Member Function Documentation

void SetData(java.io.InputStream stream, PDFDict encoding_dict, PDFArray encoding_params)

Parameters

stream: java.io.InputStream
encoding_dict: PDFDict
encoding_params: PDFArray

Returns:

void

PDFObject clone()

Returns:

PDFObject

A new PDFObject that is a copy of this object.

Makes a new copy of this PDFObject in memory, in the same document and using same direct/indirect setting as this PDFObject.

PDFObject clone(Document doc)

Parameters

doc: Document: The target document in which to create the copy.

Returns:

PDFObject

A new PDFObject that is a copy of this object in the specified document.

Makes a new copy of this PDFObject in memory, in the supplied document, using the same direct/indirect setting as this PDFObject.

PDFObject clone(Document doc, boolean indirect)

Parameters

doc: Document: The target document in which to create the copy.
indirect: boolean: If true, the copy will be an indirect object; if false, it will be direct.

Returns:

PDFObject

A new PDFObject that is a copy of this object in the specified document.

Makes a new copy of this PDFObject in memory, in the supplied document, using supplied direct/indirect setting.

PDFObject clone(PDFObject obj)

Parameters

obj: PDFObject: The reference object whose document will be used for the copy.

Returns:

PDFObject

A new PDFObject that is a copy of this object in the same document as obj.

Makes a new copy of this PDFObject in memory, in the same document as another object, using the same direct/indirect setting as this PDFObject.

PDFObject clone(PDFObject obj, boolean indirect)

Parameters

obj: PDFObject: The reference object whose document will be used for the copy.
indirect: boolean: If true, the copy will be an indirect object; if false, it will be direct.

Returns:

PDFObject

A new PDFObject that is a copy of this object in the same document as obj.

Makes a new copy of this PDFObject in memory, in the same document as another object, using supplied direct/indirect setting.

PDFObjectComparison compareTo(PDFObject rhs)

Parameters

rhs: PDFObject: the other PDFObject to compare.

Returns:

PDFObjectComparison

A PDFObjectComparison value that relates this object to the rhs object

Compares this object to another object. The result is useful for ordering or sorting PDFObjects. No other significance should be attached to the result. In particular, an unequal result indicates nothing about the type of either object.

The result is valid only within a single instance of the document.

synchronized void delete(Boolean disposing)

Parameters

disposing: Boolean

Returns:

synchronized void

synchronized void delete()

Returns:

synchronized void

void destroy()

Returns:

void

Destroys this object.

This method does nothing if this object is a direct scalar object.

If a composite object (an array, dictionary or stream) is destroyed:
All the direct objects in it are automatically destroyed.

The indirect objects in it are not destroyed.

boolean enumPDFObjects(PDFObjectEnumProc enumProc)

Parameters

enumProc: PDFObjectEnumProc: A user-supplied callback to call for each element of the object. of obj. Neither proc nor any routine called by proc may modify the object. Doing so can produce undefined results or errors. For example, if the object is an array, enumProc must not call Remove(); if the object is a dictionary, enumProc must not call Put().

Returns:

boolean

Returns true if every call to enumProc returned true. As soon as any call to enumProc returns false, the enumeration stops and EnumPDFObject() returns false.

Enumerates the elements of a PDFObject by calling a user-supplied procedure for each component of the object.
For scalars or strings, the proc is not called, and CosObjEnum() returns true.

For dictionaries, proc is called for each key-value pair. The order in which the key-value pairs are enumerated is undefined.

For arrays, proc is called with each element as the first paramater to proc, and the NULL object as the second parameter. Array elements are enumerated in ascending order of index.

For streams, proc is called once, with the stream's dictionary as the first parameter to the proc and the NULL object as the second parameter.

boolean equals(Object rhs)

Parameters

rhs: Object

Returns:

boolean

void finalize()

Returns:

void

PDFDict getDict()

Returns:

PDFDict

The stream's encoding dictionary.

The encoding dictionary for the stream. This includes all required information for decoding the stream, such as filter names and decode parameters.

Document getDocument()

Returns:

Document

the Document in which the object resides.

The Document of which this object is a member. Returns null if the Document is not known by PDFL, or if it is a temporary document.

If the Document is not null, then it shares the same internal data with other Document objects that refer to the same file. Document objects returned this way do not contribute to the internal count that keeps the Document open, and will become invalid if the main reference to the document is disposed.

java.io.InputStream getFilteredStream()

Returns:

java.io.InputStream

int getGeneration()

Returns:

int

The generation number of this indirect object.

The generation number for this object. Only indirect objects have a generation number.

int getID()

Returns:

int

The ID number of this indirect object.

The ID number for this object. Only indirect objects have an ID number.

boolean getIndirect()

Returns:

boolean

true if this object is indirect, false if it is direct.

Indicates if this object is indirect or direct.

int getLength()

Returns:

int

The length of the encoded (raw) stream data.

The encoded length of the stream in bytes.

int getPDFHashValue()

Returns:

int

The 32-bit hash value for this object.

The 32-bit hash value for this object. The hash value is used internally to quickly access the object, and is not generally useful for PDFObject users. Note that two PDFObjects with equal hash values are not necessarily equal; use Equals() to check for equality.

java.io.InputStream getStream(PDFStreamOpenMode mode)

Parameters

mode: PDFStreamOpenMode

Returns:

java.io.InputStream

int getStreamPos()

Returns:

int

The byte position of this stream within the PDF file.

The byte offset of this stream in the PDF file.

java.io.InputStream getUnfilteredStream()

Returns:

java.io.InputStream

void setDataInternal(BaseInputNozzle nozzle, PDFDict encoding_dict, PDFArray encoding_params)

Parameters

nozzle: BaseInputNozzle
encoding_dict: PDFDict
encoding_params: PDFArray

Returns:

void

String toString()

Returns:

String

A string describing this PDFStream, including its indirect/direct status and ID.

Returns a string representation of this PDFStream.